The invention relates to diagnostic imaging equipment, and more particularly relates to those parts of diagnostic imaging equipment which support the patient while the patient is undergoing an imaging study. In its most immediate sense, the invention relates to a patient handling system for use with nuclear medicine imaging equipment.
In nuclear medicine diagnostic imaging, a radioisotope is administered to the patient. The radioisotope is chosen to be taken up by an organ or structure of interest (e.g. the heart or the patient's skeleton). The patient is then placed adjacent one or more detectors. As the radioisotope emits gamma radiation, the radiation is detected by the detector(s) and used to form images of the organ or structure of interest.
In some nuclear medicine studies, the patient sits on e.g. a chair and placed e.g. so that his chest is adjacent a detector or so his torso is located between two detectors. In other studies, the patient lies horizontally while the detector(s) rotate about the patient's body axis. In still other studies, the patient lies horizontally while the detector(s) move horizontally parallel to the patient's body axis. The variety of patient positions used in nuclear medicine studies makes it advantageous to provide a patient handling system which is sufficiently versatile to make it easy to carry out many different types of nuclear medicine studies.
Additionally, when a patient lies horizontally, the way in which the patient must be supported depends upon the study which is to be conducted. In a typical whole body study, the patient lies supine with his or her arms at the sides and is most comfortably supported when both arms are supported by arm rests. For e.g. a cardiac SPECT study, wherein the patient lies supine with one or both arms above the head, either one arm or neither arm is supported on an arm rest. For a conventional 360.degree. SPECT study, both the patient's arms should be raised over the head. It would be advantageous to provide a patient handling system wherein various arm support options are available and wherein arm support could easily be provided and removed based upon the clinical requirements of the studies to be carried out.
Furthermore, for certain studies (e.g. planar whole body bone scans) the patient must be positioned so as to lie completely within the field of view of the detector(s). Because the sensitive crystal surface (and thus the field of view) of the detector(s) is smaller than the housing of the detector(s), and because the patient is frequently positioned at a location which is remote from the detector(s), it is sometimes difficult to determine whether the patient is properly positioned relative to the field(s) of view.
One object of the invention is to provide a patient handling system which is sufficiently versatile so as to make it easy to carry out many different types of nuclear medicine studies.
Another object is to provide such a system which makes it easy to provide or eliminate arm support depending upon the particular study being conducted.
Another object is, in general, to improve on known patient handling systems for use with diagnostic imaging equipment.
In accordance with the invention, there is provided a patient pallet having two sides, a proximal end and a distal end. The patient pallet is horizontally elongated and is positioned to support a human patient with the patient's body axis horizontal. In further accordance with the invention, the pallet is supported by a pedestal. The pedestal is vertically moveable so that the patient may be raised and lowered with respect to the floor. The pedestal receives the patient pallet so that the pallet can move lengthwise, parallel to the floor. As a result, the patient pallet is always supported at and adjacent its proximal end by the pedestal.
A pallet support is also provided in accordance with the invention. The pallet support is horizontally spaced from the pedestal and is so located that the distal end of the patient pallet can be supported by the pallet support when the patient pallet is moved lengthwise. In this way, the patient pallet is either supported by the pedestal alone or by the pedestal and the pallet support. In the latter instance, the patient pallet bridges between the pedestal and pallet support.
In further accordance with the invention, left and right horizontally elongated arm rests are provided. Each of these is individually securable to a corresponding one of the sides of the patient pallet and slides together with it when so secured. Thus, when a particular study makes it necessary or convenient to provide support for one or two arms, either one or both of the arm supports are secured to the patient pallet and move together with it. If no arm support is necessary or appropriate, the patient pallet moves by itself.
Advantageously, and in accordance with the preferred embodiment of the invention, indicating means are attached to each of the arm rests and move together with them. The indicating means indicate side boundaries beyond which the patient's body should not project. By properly positioning the patient with reference to the indicating means, the patient is always located within the field of view of the camera detector(s).
Advantageously, and in accordance with the preferred embodiment, the indicating means comprises two elongated flaps, each one extending parallel and adjacent to a corresponding one of the sides of the patient pallet. Each flap has a raised position in which it extends upwardly from the patient pallet and a lowered position in which it lies flat upon the patient pallet. When the patient is to be placed upon the patient pallet (e.g. by transfer from a patient gurney), the flaps lie flat so as not to present an impediment. Once a study is to be commenced, the flaps can be raised to make sure that the patient's body is not located outside the field of view of the detectors.
Further advantageously, and in accordance with the preferred embodiment of the invention, the pedestal can be moved around on the floor. This permits the pedestal and patient pallet to be moved out of the way so that the patient can be imaged while e.g. sitting upon a chair. Likewise advantageously, and in accordance with the preferred embodiment, the pedestal and the pallet support are connected together and the pallet support is raised and lowered to correspond to vertical movement of the pedestal and patient pallet. This makes it easy to slide the patient pallet horizontally so that its distal end rests upon the pallet support.